Introduction

Coating and lamination techniques are used to impart properties to fabrics which are not necessarily those naturally assumed by textile fabrics. Having widespread application across a range of technical textiles sectors, they increase functionality and durability as well as value. They can include; waterproofness, increased abrasion, stain, flame and UV resistance, retro-Reflection or Fluorescence?, anti microbial or Phase Change Materials.

These functions can be imparted using a range of application methods, dictated by the materials being processed and the required outcome, whether they are applied as a coating or laminate is also determined by this criteria. The definition between the two is a technicality relating to the application method, generally coatings are applied to a fabric in their preparatory state, often in liquid form. Lamination requires the pre-preparation of a laminate membrane that is then applied to the textile.

The application for coated and laminated textiles is widespread across a variety of technical textile sectors, these include;

Fashion, luggage and accessories- textured looks such as high shine or ‘wet’ look

PVC/Faux leather

Sports and leisure

Sail cloth

Bouncy castles

Coatings and laminates will interact differently with the fabric; this is due to the way in which they affix to the textile surface. Figure A demonstrates how a coating covers the surface of the fabric, as applied in liquid form, it is able to penetrate the fabric structure, filling the air pockets and bridging the interstices. Figure B depicts how a laminate sits on the fabric surface, the fabric retains its air pockets and the laminate has fewer points of contact.

Figure A. Schematic of a coated textile

Figure B. Schematic of a laminated textile.

As with both lamination and coating the bonding mechanism is of importance. The bonding can occur through the thermoplastic qualities of the coating or laminate, whereas it is heat set, although this is not appropriate for all materials, so solvent or water-based adhesives are used. The use of adhesives is a highly technical area, as gaining a strong yet flexible bond can be a challenge.

Fabric pre-treatment prior to coating is important, particularly its stabilisation, as some coatings bridge the interstices within the textile, and for the coating to remain functional this must remain the case. Therefore ensuring a fabric is stabilised prior to coating limits the risk of movement within the fabric structure which may impact on the coating or laminate applied.

The end product is sometimes referred to as a composite, as it is a composition of a textile and non-textile component. Many of the mechanical properties are determined by the fabric, such as tear strength, the coating largely determines the chemical properties, and the handle is often determined by both.

It is not just technical applications which utilise coating and lamination technology, the fast paced fashion market is constantly giving the technology new challenges with the need to create innovative and visually interesting looks such as a high shine, futuristic finish, or imitation animal skin.